SAILBOATS GALORE,” said
Vanessa Deleon.
“Sailboats on front window sills like candelabras for the holidays.” Such hokey touches are the sort of missteps folks make when kitting out weekend houses, said the New York interior designer. She suggests welcoming, flower-filled window boxes instead—especially if none of the home’s occupants owns even a dingy. Here, summerhouse décor goofs that make designers wince, and recommended alternatives.

Overly Urban Outfitting

“Clients tend to reproduce what they have in the city,” said Montreal-based designer
Richard Ouellette.
“They buy matching end tables from the mainstream or city-furniture stores.”

The Fix: “Make a run for the flea markets and antiques shops near your weekend house,” he suggested. “Find colorful old boxes and stack them to make the best end table, or find old wicker chairs and have them repainted.”

Excessive Bead Board

“This was the Victorian era’s version of Formica, a way to hide imperfections,” said New York designer
Kati Curtis,
who notes that the material has become a country-house cliché.

The Fix: “If you have it already, paint it white and try to make it disappear,” she said. “If not, and you want to add texture and warmth in a modern way, use a grass-cloth wallpaper.”

A Dearth of Plants

No reason to abandon indoor greenery just because you might be away for weeks at a time. “Bringing nature inside is absolutely key,” said London designer
Kelly Hoppen.

The Fix: She recommends neglect-abiding succulents and cactuses. They also complement the textures of white linen and gray seersucker, among her summer favorites. Dallas designer
Michelle Nussbaumer
adds that orchids, which don’t require much water, can also thrive.

Theme Dreck

Filling a mountain house with pine and antlers, or a beach house with seashells and purely decorative surfboards, borders on tacky. “It’s redundant,” said Baton Rouge designer
Rachel Cannon.

The Fix: “Nod to the location through texture, finishes and color,” said Ms. Cannon, who recommends using
Sherwin-Williams
’s ColorSnap app to match paint colors to nature. Ms. Curtis incorporates subtle beachy inflections like a mirror with mother-of-pearl inlay, while New York designer
Ghislaine Viñas
makes over-the-top décor palatable by simplifying it. A “hideous” mermaid lamp became an agreeable wink to the seaside when the New York designer painted it white.

Staged Produce

Using only green apples or lemons in a fruit bowl looks unnatural, said designer
James Duncan,
based in Key Biscayne, Fla.

The Fix: “Try mixing in summer vegetables with odd shapes and strong colors,” he said. “Think intriguing still life rather than a boutique hotel from the ’90s.”

LOCAL FLAVOR | In his country house in Knowlton, Quebec, designer Richard Ouellette sourced the collection of dishes from markets in the area.
Photo:
Andre Rider

Blue-and-White Mania

“Just because you’re near the water doesn’t mean everything has to be the color of it,” said Ms. Curtis.

The Fix: “Warm colors like reds and oranges complement the outdoors,” she said. “Adding contrast can actually enhance the views by day and be more interesting at night.”

Errant Towels

“Who wants to go searching for towels or see piles of sandy, wet ones?” said New York designer
Harry Heissmann.

The Fix: He recommends a hard-to-miss wicker basket of rolled-up towels by the pool or at the door, accompanied by a wicker hamper so guests can easily grab and/or drop.

Dismal Detritus

“Summer homes can become catchalls for the pieces that didn’t work in the primary home,” said Ms. Nussbaumer. “But if something wasn’t working in your main house, it probably isn’t going to in your weekend retreat either.”

The Fix: “Purchase things appropriate for the space,” she said. “You can find reasonably priced pieces from online retailers like Chairish and One Kings Lane. And of course, there’s always IKEA.”

Unchecked Clutter

Never a good thing, visual static is especially egregious in a handsome setting. “It takes away from the beauty of the environment that surrounds you,” said Ohara Davies-Gaetano, an interior designer in Corona Del Mar, Calif.

The Fix: Simplify, simplify, simplify. “Allow the design to be open and expansive so your eye can rest on the landscape that defines your locale,” she said.

Chintziness

“I’ve noticed a lot of homeowners choose low-cost, poorly made products for their summer and weekend homes,” said Nashville designer Chad James. “But in a weekend house, everything from entertaining to dragged-in sand wears on walls, flooring, linens and towels.”

The Fix: Choose quality products so that they last more than just a season, suggested Mr. James. Added Dallas-based designer
Jean Liu,
“Summers and weekends are entirely too short for uncomfortable couches, lumpy beds and dorm-room décor.”

Wall-to-Wall Beds

“People tend to cram as many beds as possible in all bedrooms,” said Charleston, S.C., designer Tyler Hill. Fearing guests might not be accommodated, hosts furnish their homes like hostels.

The Fix: “Air mattresses, believe it or not,” said Mr. Hill. “They’re easy to assemble and store.” Another option: “Makeshift bedrooms, such as an alcove off a main room, which a bed can transform into a little sleeping nook.”

Misguided Sophistication

“The idea of creating a chic, elevated, hotel-room experience in a vacation home is a wonderful goal, but it’s certainly not memorable,” said New York designer
Tamara Eaton.

The Fix: “Create eclectic rooms with lots of personality,” said Ms. Eaton, “slightly unkempt and relatively simple—rooms that don’t take themselves seriously.”

Flimsy Materials

“I find clients averse to weightier fabrics at the beach,” said New York designer
Charlie Ferrer.
“But there is such a thing as too much Belgian linen.”

The Fix: Country weather can get cold and wet. “Fine wools and luxurious cashmeres make those moments cozy,” said Mr. Ferrer. “And these materials stay much cooler in the heat than many expect.”